It is, of course, well known that alternating cycles of using and laundering fabrics and textiles, such as articles of worn clothing and apparel, will inevitably adversely affect the appearance of the fabric and textile items so used and laundered. Fabrics and textiles simply wear out over time and with use. Laundering of fabrics and textiles is necessary to remove soils and stains which accumulate therein and thereon during ordinary use. However, the laundering operation itself, over many cycles, can accentuate and contribute to the deterioration of the appearance of such fabrics and textiles.
Repeated laundering of fabrics and textiles, especially with bleach-containing laundry products, can remove dye from fabrics and textiles and impart a faded, worn out appearance as a result of diminished color intensity, and in many cases, as a result of changes in hues or shades of color. Dye fixative materials have been used in the textile indusrty to improve the washfastness of certain dyes. Typically such materials are cationic polymers which are able to form ion pairs with the dye on fabrics, thereby reducing the solubility of the dye. Such cationic dye fixative materials, however, cannot typically be used in laundry detergents due to the potential of the cationic fixative to form precipitates with the anionic surfactants that are generally employed in laundry detergent products. Such precipitation can reduce the cleaning efficiency of the detergent.
Given the foregoing, there is clearly an ongoing need to identify materials which could be added to anionic surfactant-containing laundry detergent products and which could associate themselves with the fibers of the fabrics and textiles laundered using such detergent products and thereby reduce or minimize the tendency of the laundered fabric/textiles to deteriorate in appearance. Any such detergent product additive material should, of course, be able to benefit fabric appearance without unduly interfering with the ability of the laundry detergent to perform its fabric cleaning function. The present invention is directed to detergent compositions containing certain types of dye fixative materials that perform in this desired manner.